1. Field of the Invention
The invention lies in the field of optical elements and is applied to mechanical connecting devices for optical fibers in which a plurality of optical fibers, which are arranged in parallel to one another and which end in a plug-in connector, are connected to a coupling partner arranged on a circuit board. Using a holder, this plug-in connector is arranged in a housing wall. Coupling partners can be, for example, optical transmitting and/or receiving modules or can be formed by identical or similar plug-in connectors.
European Patent Application EP 0807 837 A1 teaches a known multichannel optical coupling configuration of this type in which one or two plug connectors are assigned to a coupling partner, likewise including one or two plug-in connectors, by using a holder which is arranged in a housing wall (back panel). This holder includes an outer housing having four walls that run toward one another at right angles and an inner housing arranged in the outer housing such that it can be moved axially, that is to say in the Z direction, and at right angles thereto, that is to say in the X/Y direction. The inner housing is used to accommodate and axially fix one or both plug-in connectors, which each contain a multichannel optical fiber end piece arranged in a housing in a known way. This multichannel optical fiber end piece is referred to as a xe2x80x9cferrulexe2x80x9d and is arranged at the end of a multichannel optical fiber cable (See also Issued German Patent DE 195 39 549 C1, International Publication WO 97/34176, European Patent application EP 0803 749 A1, and European Patent application EP 0803 748 A1). A coupling partner is arranged on a circuit board using a connector housing. The connector housing can be plugged into the outer housing of the holder, to which end both housings are provided with guide surfaces and interengaging guide grooves and webs. The connector housing is also provided with latching hooks, arranged in a resilient manner, which engage in corresponding openings in the inner housing of the holder and in this way brace the optical fiber end pieces (ferrules) of the plug-in connectors to be coupled axially against each other. The latching and locking elements arranged in the inner region of the holder make disassembling this coupling configuration more difficult.
It is further known, to provide diodes as coupling partners for an optical plug-in connector arranged at the end of an optical fiber cable. These diodes are arranged on a circuit board and a plug-in inlet is provided in order to retain the plug-in connector (See U.S. Pat. No. 5,138,680 and German Patent Application DE 42 05 568 A1). In a coupling configuration which is also known, the plug-in connectors, which are substantially identically designed and arranged in mirror-image fashion in relation to each other, are connected to each other within a two-part adapter (See European Patent Application EP 0712 015 A2). In another known configuration, in each case, a plurality of plug-in connectors are assigned one half of a two-part coupling housing. The two differently designed halves of the coupling housing interengage with finger-like guide wings and corresponding guide grooves and also with retaining collars (See International Publication WO 97/34 176).
It is accordingly an object of the invention to provide a multichannel optical coupling configuration which overcomes the above-mentioned disadvantages of the prior art apparatus of this general type.
With the foregoing and other objects in view there is provided, in accordance with the invention, a multichannel optical coupling configuration, which includes a plug-in connector, a coupling partner arranged on a circuit board and a holder to be arranged in a recess in a housing wall (back panel) to guide and retain the plug-in connector and to guide the coupling partner. A multichannel optical fiber end piece (ferrule) is arranged in an axially resilient manner in the housing of the plug-in connector and the coupling partner has a plug-in inlet to connect to the plug-in connector, in such a way that the coupling configuration, while being easy to mount and disassemble, permits the compensation even of relatively large tolerances between the board and the back panel transversely with respect to the plug-in direction, as well as the compensation of angular tolerances.
In order to achieve this object, the invention uses some design features which are known for coupling configurations of this type. To some extent, these features are placed in a different operative conjunction and new design features are added. These measures lead to a coupling configuration in which the plug-in connector is locked in the holder such that it can be unlocked in a simple way, and in which the coupling partner can be locked accurately in position with the plug-in connector. In addition, the housing wall carrying the holder is completely relieved of plug forces, and only compressive and tension forces have to be exerted on the plug-in connector or the coupling partner in order to couple and uncouple coupling partner and the plug-in connector. This is achieved by using a special configuration of the holder, including the outer and inner housing, and the parts of the plug-in connector and the coupling partner that come into an operative connection with the inner housing of the holder.
Accordingly, first of all the holder includes an outer housing, which is arranged such that it can be displaced at right angles to the plug-in direction, and an inner housing. The inner housing is arranged such that it can rotate in the outer housing. At the same time, in order to retain the plug-in connector in the holder on the inner housing, a locking element designed as a two-armed lever is mounted. One lever arm of the locking element is subject to the action of a spring. Then, in order to latch the plug-in connector to the coupling partner, the housing of the plug-in connector is provided with at least one resilient latching arm having a latching lug, and the coupling partner is provided with a recess arranged in the plug-in inlet to accommodate the latching lug. For the invention, it is also important that the plug-in inlet of the coupling partner is provided with finger-like guide elements which extend in the plug-in direction, which have operative faces arranged in a stepped manner. Guide faces are assigned on the inner housing of the holder to couple the coupling partner in an accurately fitting manner to the plug-in connector, and also operative faces for unlocking the locking element on the lever arm of the locking element which is subject to the action of a spring. The recess arranged in the plug-in inlet and the operative faces on the finger-like guide elements of the plug-in inlet are staggered in the plug-in direction in such a way that when the coupling partner is joined to the plug-in connector retained in the holder, the locking element arranged in the holder is unlocked after the latching lug of the plug-in connector has latched in the recess in the plug-in inlet.
A coupling configuration configured in this way permits adequate compensation of tolerances between the parts arranged in the housing wall and the parts of the coupling configuration arranged on the circuit board. It is also possible for angular errors with regard to the configuration of the coupling partner on the circuit board to be compensated for by using the pivotable configuration of the inner housing of the holder. The configuration of the locking element as a two-armed, spring-loaded lever permits complete relief of the load on the housing wall from the forces acting between the plug-in connector and the coupling partner in the coupled state, and also enables secure retention of the plug-in connector when the coupling is released. It is possible nevertheless for this retention to be released in a simple way.
In order to be able to implement the latching and locking functions provided when the plug-in connector and the coupling partner are guided together, with the most compact design of the coupling configuration possible, in a development of the invention, the plug-in connector housing is of a flat design and one of its broad sides has a sliding key for the correct lateral assignment to the holder. Each of the narrow sides of the plug-in connector housing has a resilient latching arm with a latching lug. Furthermore, the locking element mounted in the inner housing is assigned to a broad side of the plug-in connector and is configured as a rocker which extends in the plug-in direction. The end of the rocker that is subject to the action of the spring, is designed as a locking lug to engage in a recess extending in the plug-in direction in the plug-in connector housing. The other end of the rocker is freely accessible. In this connection, the locking lug of the locking element has wing-like extensions that run transversely with respect to the plug-in direction. Inclined faces of the locking element, that are for unlocking the locking element, are assigned to the finger-like guide elements of the plug-in inlet of the coupling partner. The recesses in the plug-in inlet of the coupling partner are dimensioned in the plug-in direction such that they permit a relative movement between the plug-in inlet and the plug-in connector housing in the latched state. Finally, the distance, in the plug-in direction, from the latching edge of the respective recess in the plug-in inlet to the inclined faces on the finger-like guide elements of the plug-in inlet is less than the sum of the distances provided in the plug-in direction from the latching lugs of the plug-in connector to the recess provided in the plug-in connector housing for the locking element, and the distance from the recess for the locking element to the wing-like extensions.
The intended compact design is further improved if the recess provided in the plug-in connector for the access of the locking lug is provided in a web forming the sliding key.
In order also to ensure automatic unlatching of the plug-in connector and the coupling partner when the new coupling configuration is being released under the action of tensile forces, in a further refinement of the invention, each latching arm of the plug-in connector housing is provided with a web which is arranged behind the latching lug in the plug-in direction and which runs transversely with respect to the plug-in direction. An inclined plane is assigned in order to unlatch the latching lug on the inner housing of the holder. The distance provided, in the plug-in direction, from the recess in the plug-in connector housing to the web is greater than the distance provided, in the plug-in direction, from the spring-loaded end, designed as a locking lug, to the lever designed as a rocker from the inclined plane provided in the inner housing.
A configuration of this type, with which the unlatching between the plug-in connector housing and the coupling partner, during the release of the coupling, is coordinated with the locking operation between the plug-in connector and the holder, is of special advantage when two or more plug-in connectors or coupling partners are arranged, since all of the coupling partners are unlatched without manual intervention as they are pulled out of the circuit board.
In a further refinement of the invention, the outer housing of the holder can be fixed in the housing wall by a supporting clip. This enables the coupling configuration to be easily mounted.
When a plurality of plug-in connectors are assigned to one housing wall, in order to be able to arrange the plug-in connectors in a space-saving manner as much as possible, it is advantageous if two plug-in connectors and the two holders are arranged in a mirror image fashion in relation to each other in the same recess in the housing wall. This space-saving configuration can be further perfected if the two associated coupling partners, which for example, are formed as optical receiving and/or transmitting modules, but which can also be formed as plug-in connectors, are arranged in a mirror image fashion on the two sides of the circuit board. If in this connection, the outer housing of the holder is constructed from a plastic part and a sheet-metal part in such a way that the mutually facing wall parts of two holders arranged in the same recess in the housing wall consist of thin sheet-metal parts, then this configuration leads to a minimum spacing between the two outer housings, which makes a high packing density possible for the coupling partners arranged on the circuit board. In this way, a distance between the optical axes of two adjacent coupling partners of less than 9 mm can be achieved.
In order to be able to optimally align the plug-in connectors that are locked in the holder in relation to the coupling partners that are arranged on the circuit board, both in the plug-in direction and also transversely thereto, a flat design of the finger-like guide elements of the plug-in inlet is recommended. The tips of the guide elements are provided with bevels serving to align the holder. The guide face, pointing outward, of a guide element is provided with a web-like elevation that is arranged to be set back opposite the respective finger tip. The end of the elevation facing the finger tip has an inclined face used to engage in the locking element.
The intended optimum alignment also requires a specific configuration of the holder, in particular of its inner housing. First of all, in a further refinement of the invention with respect to the outer housing, it is expedient that the outer housing includes a U-shaped plastic part and a likewise U-shaped sheet metal part placed on the plastic part in the manner of a clip. The sheet-metal part is provided with latching tongues to retain the outer housing of the supporting clip. In order at the same time to ensure the preconditions for the pivotable configuration of the inner housing in the outer housing, the sheet-metal part is provided with a pin and the plastic part is provided with a hole. This pin and this hole are operatively connected to a hole and a pin which are arranged on two opposite walls of the inner housing, which includes a plastic part with a substantially box-like outer contour. In addition, guide faces formed with webs and guide grooves for the plug-in connector and for the plug-in inlet of the coupling partner are also provided on the two opposite walls of the inner housing. In order to form these guide faces and guide grooves, there are two webs of an L-shaped cross section, which are carried by one wall of the inner housing and which between them, with the outer L-shaped faces, form a guide groove for the sliding key in the form of a web arranged on the plug-in connector housing. At the same time, the inner L-shaped faces of the webs, form guide faces for the finger-like guide elements of the plug-in inlet. A further web for aligning the finger-like guide elements is arranged laterally beside the L-shaped webs in each case.
The most compact and easy-to-mount configuration of the coupling configuration is provided by using pins to mount the locking element, which is designed as a rocker, in the L-shaped webs in such a way that the locking lug projects into the guide groove for the sliding key.
In order that during the insertion of the plug-in inlet of the coupling partner, the movably arranged holder can assume the optimum position for joining the coupling partner and the plug-in connector as snugly as possible, that is to say without the risk of canting, it is advantageous if the webs that are arranged in the inner housing of the holder begin behind the pins and holes that are provided for pivotably mounting the inner housing, as viewed in the plug-in direction of the coupling partner. The force action points for aligning the inner housing in this case lie behind the pivot axis of the inner housing, as viewed in the plug-in direction.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a multichannel optical coupling configuration, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.